U.S. Pat. No. 5,603,845, WO 96/16713, WO 96/16714 and WO 96/16715 disclose a method and a container for separating a component, such as fibrin monomer, from blood or plasma by centrifugation, whereby blood is fed to a first annular chamber in a device, where the annular chamber is defined by a cylindrical outer wall and a cylindrical inner wall, both walls extending coaxially about a common axis, as well as by a top wall and a bottom wall. The top wall is formed by a piston body displaceable within the first chamber. This method involves a centrifugation of the device about the said common axis to substantially separate blood into a cell fraction and a plasma fraction followed by the resulting plasma fraction being transferred while influenced by the piston body to a second chamber defined by an outer cylindrical wall. The outer cylindrical wall extends coaxially with the said common axis, whereby a fraction with fibrin monomer is caused to be separated in the second chamber while a suitable enzyme is being added. The separation of fibrin monomer from the plasma fraction in the second chamber is carried out during continued centrifugation whereby a polymerized fibrin is deposited on the cylindrical outer wall of said second chamber, whereafter the fluid fraction collected at the bottom of the second chamber is transferred while influenced by the piston body to the first chamber. The fraction with polymerized fibrin deposited on the cylindrical wall in the second chamber is caused to be dissolved by addition of a solvent and by centrifugation, whereafter it is transferred to a receiving container placed within the piston rod by passing after enzyme capture and filtration, whereby a fibrin monomer-containing solution is provided.
U.S. Pat. No. 5,603,845 discloses an apparatus for initiating such a centrifuging. This apparatus comprises a housing which is basically divided into three compartments, viz. an upper compartment, a central compartment, and a lower compartment. The container with the fluid to be separated is placed in the central compartment. It is placed on a rotatable supporting turntable which is rotatably journalled on a journalling shaft, said shaft constituting an output shaft of a motor which is housed in the lower compartment. Accordingly, this motor constitutes a means for generating the high rotational speed at which the container is to be rotated about its central axis at a number of process steps. The latter process steps correspond to the separating process which the fluid is to be subjected to in order to be separated into the desired fluid components. The container is retained on the supporting turntable by means of gripping means engaging openings shaped along the lower rim of the container. A motor is arranged in the upper compartment. The said motor co-operates with a gripping means which is rotatably journalled and adapted to be vertically displaced so as to engage and co-operate with the piston rod of the container. This centrifuge apparatus corresponds to the apparatus described in the introduction to the specification.
EP 592242 describes a novel fibrin sealant method which prepares and utilizes fibrin monomer which is understood to refer to fibrin I, fibrin II or des BB fibrin. The monomer can be prepared using apparatus and methods as described in the aforementioned U.S. Pat. No. 5,603,845, WO 96/16713, WO 96/16714 and WO 96/16715. Essentially, plasma fibrinogen is subjected to an enzyme which catalyzes the cleavage of fibrinopeptide A and/or B from fibrinogen, i.e., thrombin or a thrombin-like enzyme which converts fibrinogen to fibrin. Nondynamic fibrin monomer compositions can thereafter be obtained, for example, by solubilizing the resulting non-crosslinked fibrin polymer in a low Ph, i.e., about pH-4, buffer where the fibrin monomer is prevented from polymerizing until the pH is raised.